1. Field of the Invention
The present invention generally relates to a coated parallel twin wire wiring method and apparatus for wiring coated parallel twin wires on a printed circuit board of an electronic computer.
Conventionally, in a printed circuit board of an electronic computer, a wire is provided in order to cope with and design change and eliminate defects. Such a wire is coated for establishing electric insulation and is a twin wire member consisting of a signal line and a ground line in order to prevent the influence of noise. In a device using coated twin wires as described above, it is necessary to prevent the printed circuit board from being damaged and to connect the wires to respective desired pads.
2. Description of the Prior Art
An apparatus for automatically connecting coated twin wires to pads or the like is disclosed in IBM J.RES. DEVELOP VOL. 27, NO. 6, NOVEMBER 1983. This automatic wiring apparatus uses a twisted pair line composed of a pair of twisted wires, removes the coating, and simultaneously bonds the two wires by means of heat of a bonder. The pressure of the bonder is as high as approximately 100 gr.
Recent printed circuit boards have a high pattern integration density and have a structure in which wiring patterns are formed on upper and lower surfaces of a thin film made of polyimide and provided in the vicinity of surfaces of the printed circuit boards.
Recently, it has been required that the printed circuit boards use parallel twin wires instead of a pair of twisted wires in order to improve the effect of noise elimination.
Nowadays, the thickness of the polyimide thin film, which has been 30 .mu.m in the past, has become as thin as half of the above past value, namely, 15 .mu.m. If a pressure as large as 100 gr is applied to the polyimide thin film, a thin film part thereof serving as an insulating film may be damaged.